Why is a destiny achieved by the decisions you have made preferable to a destiny that comes from chance or luck?

This is, of course, a matter of opinion.  However, you can
argue that the "destiny" that you acheive on your own is better because it is more
fulfilling and rewarding.

Think about the feeling that
comes along with making money.  A person who makes a fortune based on their own
decisions and efforts can feel proud of themselves.  They can know that it was their
hard work and/or their wise decisions that made them succeed.  By contrast, a person who
wins the lottery merely feels lucky.  They know that they did not do anything to earn or
to deserve the money.  It is a much less satisfying feeling because they know that this
destiny came to them just by luck and not through any effort of their
own.